International Journal of Innovative Technology and Exploring Engineering (IJITEE) ISSN: 2278-3075, Volume-2, Issue-3, February 2013 Evaluation of Groundwater for Irrigational Purposes in Cumbum Valley Theni District Tamilnadu India R. Ayyandurai, M. Suresh, S. Venkateswaran ABSTRACT- To evaluate the groundwater quality for irrigational purposes in Cumbum Valley, Theni District, Tamil II. STUDY AREA Nadu covering a total area of about 1485.62 km2 55 groundwater samples was collected from dug and bore wells in the various Study area located in the whole Taluk of Uttamapalyam and locations of study area. The samples were analyzed for physico- a small part of Periyakulam Taluk, situated in the western chemical and calculated parameters viz., Ca+2, Mg+2, Na+, K+, corner of Madurai district of Tamil Nadu. It lies between - - - - CO3 , HCO3 , Cl , SO4 and Kelley’s ratio, SAR values, Mg- latitudes 9°34' N to 10°10' N and longitudes 77°10' E to hazards, RSC have been worked out to know the suitability of the 77°31' E and falls within the survey of India toposheets 58 groundwater quality for irrigational purpose. Majority of the F/8, 58 G/1, 58 G/2, 58 G/5 and 58 G/6. The extent of the hydrochemical facies were identified using Piper trilinear area is about 1485.62 km2. The length of the valley along diagram. It reveals that the subsurface water is alkaline earth NE-SW direction is about 60 km and its width is about 28 (Ca+Mg) then alkalies (Na+K) type. The groundwater samples fall under class-I based on Doneen’s classification and good to km. Fig.1. permissible category in the Wilcox classification. According to the SAR values plotted in the USSL diagram, most of the III. METHODOLOGY groundwater samples belong to C3-S1 (41.82%) class indicating Fifty five water samples were collected during the year 2012 high salinity and low sodium water, which can be used for almost from different dug wells which are almost uniformly all types of soil with little danger of exchangeable sodium that the groundwater could be used for all types of crops on soils of distributed over the study area. Before a well water sample medium to high permeability. is taken, the well should be pumped for some time so that the sample will represent the Groundwater from which the Keywords: Cumbum Valley, Doneen’s diagram, Irrigational, well is field. All bottles should be rinsed with the water to , Wilcox diagram USSL (U.S. Salinity Laboratory diagram). be sampled before the sample for analysis is collected. If water samples are collected in glass bottles, sufficient air I. INTRODUCTION space may be provided, but if polythene bottles are used The Indian government and scientists have carried out a they may be provided, but if polythene bottles are used they number of studies on groundwater resources in Tamil Nadu, may be completely filled. Groundwater samples analyzed in focusing mainly on utilization surveys and prediction of the laboratory for major cations and anions EC, pH and evolving trends, reserve estimation, and system assessment. Electrical Conductance were measured within a few hours Hydro-chemical studies of water resources have been few, by using Elico pH meter and conductivity meter. Ca and Mg particularly with respect to interactions among surface were determined titrimetrically using standard EDTA water, groundwater, and aquifers, because Tamil Nadu is method and chloride was determined by silver nitrate one of the leading agricultural states. The study area titration (Vogel, 1968) method. Carbonate and bicarbonate (Cumbum Valley watershed), Theni district, Tamil Nadu, were estimated with standard sulphuric acid. Sulphate was India. determined a gravimetrically by precipitating BaSO4 from Geochemical processes in groundwater involve the BaCl2. Na and K were determined by Elico flame interaction of country rocks with water, leading to the photometer (APHA, 1996). Sodium Absorption Ratio (SAR) development of secondary mineral phases. The principles was calculated by dividing sodium with the root of half governing the chemical characteristics of groundwater well calcium and magnesium as described by Richard (1954). documented in many parts of the world. (Garrels and Christ, 1965; Stumm and Morgan, 1970; Swaine and Schneider, IV. RESULTS AND DISCUSSION 1971; Kimblin, 1995; Raju, 1998). The main objectives of groundwater characteristics in the In the present study, groundwater samples have been study area results are given in Table 1. The interpretation of collected and analyzed for major Cations and Anions. The the groundwater quality data for irrigation has been carried irrigational parameters viz., EC, Kelley’s ratio, SAR values, out as per guidelines given by Ayers (1977) and Christiansen Mg-hazards, HCO3 and RSC have been worked out to et al., (1977). understand the suitability of the groundwater for irrigational purpose. A. Sodium Absorption Ratio The sodium or alkali hazard in groundwater for irrigation is determined by the absolute and relative concentration of Revised Manuscript Received on February 06, 2013. cations and is expressed in terms of Sodium Absorption R. Ayyandurai, Department of Geology, Periyar University, Salem-11, Ratio (SAR). There is a significant relationship between India. SAR values of irrigation water M. Suresh, Department of Geology, Periyar University, Salem-11, India. and the extent to which sodium S. Venkateswaran Department of Geology, Periyar University, Salem- is absorbed by the soil. If 11, India. groundwater used for Published By: Blue Eyes Intelligence Engineering Retrieval Number: C0461022313/2013©BEIESP 183 & Sciences Publication Evaluation of Groundwater for Irrigational Purposes in Cumbum Valley Theni District Tamilnadu India irrigation is high in sodium and low in calcium, the cation- The chemical quality data of the investigated area are used exchange complex may become saturated with sodium. in Pipers Trilinear Diagram for graphical analysis (Fig. 2). It SAR = (All ions in epm) reveals that water is mostly of alkaline earth exceeds Na Ca Mg alkalies in the post monsoon season. 2 F. Doneen's Permeability Index A simple method of evaluating the high sodium in water is The soil permeability is affected by long term use of the Sodium Absorption Ratio. (SAR). Calculation of SAR irrigation water. It is influenced by sodium, calcium, value for a given groundwater provides a useful index of the magnesium and bicarbonate contents of soil. Doneen (1964) sodium hazard of that water for soils and crops. Classification has evolved a criterion for assessing the suitability of water of water with reference to SAR (Herman Bouwer, 1978). A for irrigation based on Permeability Index (PI): low SAR of 0 to 6 indicates No Problem from sodium; Na HCO Increasing Problem is between 6 to 9 and Severe Problem is PI = 3 100.........................(1) above 9. The lower the ionic strength of solution, the greater Ca Mg Na sodium hazards for a given SAR. The value of SAR in the Na, Ca etc. values in epm groundwater samples of the study area ranges from 0.1 to The majority of the samples fall under class-I (Fig.3) under 6.99 during post-monsoon (Table 2). All samples fall under sampling programs as per Doneen’s classification (Table 4), the category of No Problem except one sample is fall under which indicates that groundwater is good for irrigation. the increasing Problem category. G. Wilcox Diagram B. Kelley’s Ratio Wilcox (1955) used sodium % and specific conductance in Kelley et al., (1940) have suggested that the sodium problem evaluating the suitability of groundwater to irrigation. in irrigational water could very conveniently be worked out Sodium-percentage determines the ratio of sodium to total on the basis of the values of Kelley’s ratio. Groundwater cations viz., sodium, potassium, calcium and magnesium. having Kelley’s ratio more than one is generally considered All concentration values are expressed in equivalents per as unfit for irrigation. The Kelley’s ratio has been calculated million. The results (Table 5) show that the groundwater for all the water samples of the study area. It varies from near the upstream is good for irrigation and the 0.09 to 2.66 epm (Table 1). Groundwater having more than contamination are found to be high near the downstream one is generally considered as unfit for irrigation. The (Fig.4). This may be due to the effluents from the industries Kelley’s ratio has been calculated for all the groundwater as well as the domestic sewages directed into the river. samples of the study area. The formula used in the H. Ussl Diagram estimation of this ratio is expressed as, Na U.S. Salinity Laboratory diagram (1954) interpretation is Kelley’s Ratio = all ions in epm given in the Fig.5. The two most significant parameters of Ca Mg sodium and salinity hazards indicate usability for C. Residual Sodium Carbonate agricultural purposes. USSL classification of groundwater Residual Sodium Carbonate is defined as in the study area is given in Table 6. Twenty three locations RSC CO3 HCO3 Ca Mg where all (41.82 %) samples occur within C3–S1 category. These concentrations are expressed in epm. The water having categories are predominant in the study area and accordingly excess of carbonate and bicarbonate over the alkaline earth it is interred that the groundwater in those areas suitable for mainly calcium and magnesium, in excess of permissible irrigation purpose. limits affects irrigation unfavorably (Eaton 1950 and Richards 1954). Table - 3 shows that 96% of samples are V. CONCLUSION safe for irrigation purpose. The rest are unfit for irrigation In this study, the assessment of groundwater for irrigation use in the post monsoon season. The range of residual has been evaluated on the basis of various guidelines. Piper sodium carbonate in groundwater in the investigated area trilinear diagram interpretations were made to know the varies from -18.92 to 2.77 epm.